A dynamic access memory (DRAM) is one of the important semiconductor devices in the semiconductor industry. As the dimensions of the DRAM cell decreases, metal resistivity of a memory cell capacitor increases, and leakage also drastically increases. Increased storage capacity of DRAM cell capacitors is continually required large while the dimensions of the cell area shrink. The scaling down problem of the metal and the oxide is becoming a serious obstacle to higher device density.